This research sought to understand the role that sexual relationships play in marriages at three different stages of the family life cycle. The results showed that participants consider sex to be an important element of marriage, but it has different roles for men and women. Husbands seek pleasure and relaxation in orgasm. For women, sex seems to have a more psychological function, as they value romanticism and intimacy more. Marital and sexual satisfaction are directly associated, although the sexual satisfaction of the wife seems to depend on the conjugal satisfaction, and for men, the conjugal satisfaction seems to depend more on the sexual satisfaction. It has been realized that the function of sex and the way of satisfying oneself sexually have not changed with new phases of the family life cycle, but each phase has brought challenges that can directly interfere in the couple's relationship, generating tensions and conflicts.